All right? The first one is, that test has to involve-- shouldn't have to, the value of some variable.

好不好？第一件事是，循环开始的测试必须必须-不是一定，一些变量的值。

麻省理工公开课 - 计算机科学及编程导论课程节选

The basic definition-- the expected value of some random variable x--E--I guess I should have said that a random variable is a quantity that takes on value.

最基本的定义,某一个随机变量X的期望值E,我应该提到过,随机变量是一个可以取值的数

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